Grinding method and ogs substrate

ABSTRACT

An OGS substrate and a grinding method thereof are provided. The OGS substrate includes a base substrate, wherein a shielding pattern is formed inside a periphery region of the base substrate, a reference mark is formed above the shielding pattern, the grinding method comprises: grinding an edge of the base substrate to form a chamfer; identifying edges of the reference mark and the base substrate; calculating a position distance between an outer edge of the reference mark and the edge of the base substrate corresponding thereto based on the identified edges of the reference mark and the base substrate; judging whether the position distance is smaller than a first distance; if it is judged that the position distance is smaller than the first distance, stopping grinding; otherwise, continuing to grind.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Chinese Patent ApplicationNo. 201610840042.5 filed on Sep. 21, 2016, entitled “a grinding method,an OGS substrate and a manufacturing method of an OGS mother substrate”,the disclosure of which is hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

The present disclosure relates to a field of display technology, andparticularly to a grinding method and an OGS substrate.

BACKGROUND ART

The One Glass Solution (OGS) touch screen has characteristics oflightness, thinness, excellent light transmission and so on, thereforethe OGS technology has gradually become a dominant technology in thetouch industry.

SUMMARY

In view of at least one of above problems in the prior art, a grindingmethod, an OGS substrate and a manufacturing method of an OGS mothersubstrate are provided.

To realize the above object, this disclosure provides a grinding methodfor grinding an edge of an OGS substrate, wherein the OGS substratecomprises a base substrate, a shielding pattern is formed inside aperiphery region of the base substrate, a reference mark is formed abovethe shielding pattern, a color of the reference mark is different fromthat of the shielding pattern, and an orthographic projection of thereference mark on the base substrate falls into an orthographicprojection of the shielding pattern on the base substrate, and whereinthe method comprises:

grinding an edge of the base substrate so as to form a chamfer;

identifying an edge of the reference mark and the edge of the basesubstrate;

calculating a position distance between an outer edge of the referencemark and the edge of the base substrate corresponding to the outer edgeof the reference mark based on the identified edges of the referencemark and the base substrate;

judging whether the position distance is smaller than a first distance;

in a case that it is judged that the position distance is smaller thanthe first distance, stopping grinding; and in a case that it is judgedthat the position distance is larger than or equal to the firstdistance, continuing to grind the edge of the base substrate.

Optionally, after it is judged that the position distance is smallerthan the first distance, the grinding method further comprising:

judging whether the position distance is smaller than a second distance,wherein the second distance is smaller than the first distance, wherein

in a case that it is judged that the position distance is larger than orequal to the second distance, it is identified that a grinding amount ofthe OGS substrate is normal, and in a case that it is judged that theposition distance is smaller than the second distance, it is identifiedthat the grinding amount of the OGS substrate is excessive.

Optionally, a width of the reference mark ranges from 100 μm to 200 μm.

Optionally, a color of the shielding pattern is black, and a color ofthe reference mark is white.

To realize the above object, the present disclosure provides an OGSsubstrate comprising:

a base substrate including a central region and a periphery region;

a touch structure formed in the central region; and

a shielding pattern formed in the periphery region; and

a reference mark formed above the shielding pattern, wherein

a color of the reference mark is different from that of the shieldingpattern;

an orthographic projection of the reference mark on the base substratefalls into an orthographic projection of the shielding pattern on thebase substrate;

a chamfer is formed at an edge of the base substrate; and

a position distance between an outer edge of the reference mark and theedge of the base substrate corresponding to the outer edge of thereference mark is within a first range.

Optionally, a width of the reference mark ranges from 100 μm to 200 μm.

Optionally, a color of the shielding pattern is black, and a color ofthe reference mark is white.

Optionally, the reference mark is of a multilayer structure of MoAlMo.

Optionally, the touch structure includes a touch electrode and a metalwire connected to the touch electrode, and wherein

the reference mark is provided in a same layer as the metal wire.

Optionally, the reference mark includes a plurality of sub-marksseparated from each other.

Optionally, the first range is from 200 μm to 250 μm.

To realize the above object, the present disclosure provides amanufacturing method of an OGS mother substrate, comprising steps of:

forming a shielding pattern on a base substrate, wherein the basesubstrate is divided into a plurality of substrate areas, each of whichincludes a central region and a periphery region surrounding the centralregion, and the shielding pattern is formed in the periphery region;

forming a touch structure in each central region on the base substrate;and

forming a reference mark above the shielding pattern, wherein a color ofthe reference mark is different from that of the shielding pattern, andan orthographic projection of the reference mark on the base substratefalls into an orthographic projection of the shielding pattern on thebase substrate.

Optionally, the step of forming the touch structure includes: forming atouch electrode and a metal wire connected to the touch electrode, andwherein

the reference mark and the metal wire are formed by a single patterningprocess.

Optionally, the step of forming the reference mark above the shieldingpattern further includes: forming the reference mark with a widthranging from 100 μm to 200 μm.

Optionally, the step of forming the reference mark above the shieldingpattern further includes: forming the reference mark so that a position.distance between an outer edge of the reference mark and an outer edgeof the shielding pattern ranges from 100 μm to 200 μm.

Optionally, a color of the shielding pattern is black, and a color ofthe reference mark is white.

Optionally, the reference mark is of a multilayer structure of MoAlMo.

Optionally, the step of forming the reference mark above the shieldingpattern further includes: forming the reference mark including aplurality of sub-marks separated from each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a CNC grinding process in the prior art;

FIG. 2 is a diagram showing another CNC grinding process in the priorart;

FIG. 3 is a flow chart of a manufacturing method of an OGS mothersubstrate in a first embodiment of the present disclosure;

FIGS. 4a to 4c are diagrams showing various stages of manufacturing theOGS mother substrate by using the manufacturing method shown in FIG. 3;

FIG. 5 is a top view of a substrate area shown in FIG. 4 c;

FIG. 6 is a cross sectional diagram showing a periphery region on oneside of the substrate area shown in FIG. 5;

FIG. 7 is a flow chart of a grinding method provided in a secondembodiment of the present disclosure;

FIG. 8 is a diagram showing a case that an edge of the OGS substrate isbeing ground in the present disclosure;

FIG. 9 is a flow chart of a grinding method provided in a thirdembodiment of the present disclosure;

FIG. 10 is a structural diagram of an OGS substrate provided in a fourthembodiment of the present disclosure;

FIG. 11 is a cross sectional diagram showing a periphery region on oneside of the OGS substrate shown in FIG. 10.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In order to make a person skilled in the art understand solutions in thepresent disclosure better, a grinding method, an OGS substrate and amanufacturing method of an OGS mother substrate provided in the presentdisclosure will be described in detail below in conjunction with theaccompanying drawings.

At present, a manufacturing process of an OGS touch screen includes aSensor process procedure and an OGS process procedure. The Sensorprocess procedure mainly includes manufacturing a touch structure andmanufacturing a first shielding pattern (a first screen printing). Bythe Sensor process procedure, an OGS mother substrate may bemanufactured. The OGS process procedure mainly includes: cutting the OGSmother substrate, CNC (Computerized Numerical Control) grinding the OGSsubstrate, a second screen printing, a substrate strengthening andassembling a printed circuit board.

FIG. 1 is a diagram showing a CNC grinding and a second screen printing.As shown in FIG. 1, after the CNC grinding is completed, forming a blankregion 11 between positions corresponding to a first shielding pattern(first BM) 5 a and a chamfer 10 on a base substrate 1; forming a secondshielding pattern (second BM) 5 b above the blank region 11 through asecond screen printing so as to prevent light from leaking fromperiphery of the OGS substrate.

It is found in practical applications that, the process of the secondscreen printing is difficult, thus light leakage and ink pilling arelikely caused and the defective rate of products is higher.

FIG. 2 is a diagram showing another. CNC grinding process. As shown inFIG. 2, in order to solve the above problems, a second BM Skip process(that is, the second screen printing process is skipped over) isintroduced by the manufacturer. Specifically, during the first screenprinting, the first BM 5 a is designed to be larger, so that an edge ofthe first BM 5 a is directly in contact with an edge of the chamfer 10of the formed OGS substrate. In order to prevent light from leaking fromperiphery of the OGS substrate as much as possible, during the CNCgrinding, the chamfer 10 of the formed OGS substrate may be continued tobe ground off a small length after the edge of the chamfer 10 has beenin contact with the edge of the first BM 5 a.

However, when monitoring the grinding amount of the CNC grinding processprocedure by using a Charge Coupled Device (CCD), since the chamfer 10and the first BM 5 a both are exhibited as black in the CCD, after thechamfer 10 comes into contact with the first BM 5 a, black is shown inthe view filed of the CCD, it is difficult to continue to monitor thegrinding amount of the OGS substrate, therefore, problems of excessivegrinding amount and too small size of the formed OGS substrate are easyto occur.

First Embodiment

FIG. 3 is a flow chart of a manufacturing method of an OGS mothersubstrate in a first embodiment of the present disclosure; FIGS. 4a to4c are diagrams showing various stages of manufacturing the OGS mothersubstrate by using the manufacturing method shown in FIG. 3; FIG. 5 is atop view of a substrate area shown in FIG. 4c ; and FIG. 6 is a crosssectional diagram showing a periphery region on one side of thesubstrate area shown in FIG. 5. As shown in FIGS. 3 to 6, themanufacturing method of an OGS mother substrate comprises followingsteps 101 through 103.

Step 101, forming a shielding pattern on a base substrate.

With reference to FIG. 4a , the base substrate 1 is divided into aplurality of substrate areas 2 as required, each of the substrate areas2 includes a central region 4 and a periphery region 3 surrounding thecentral region 4.

It should be noted that, a case of dividing one base substrate 1 intofour substrate areas 2 as shown in drawings is just illustrative, butnot to limit solutions of the present disclosure.

In the step 101, the shielding pattern 5 is formed in the peripheryregion 3 of each substrate area 2 through one patterning process. Theshielding pattern 5 is used to prevent light from leaking from edges ofthe produced OGS substrate. In this embodiment, a distance between anouter edge of the shielding pattern 5 and an edge on a side,corresponding to the outer edge of the shielding pattern 5, of thesubstrate area 2 to which the shielding pattern 5 belongs is about 250μm.

It should be noted that the patterning process in this disclosurespecifically refers to a process including a photoresist coating, anexposure, a development, an etching, a photoresist peeling off and soon.

Optionally, the shielding pattern is made of black material.

A step 102, forming a touch structure in each central region on the basesubstrate.

As shown in FIG. 4b , a touch structure 6 is formed in the centralregion 4 of each of the substrate regions 2, the touch structure 6includes: a touch electrode 7 and a metal wire 8 connected to the touchelectrode 7. The metal wire 8 communicates a signal with the touchelectrode 7 connected therewith so as to cooperate with the touchelectrode 7 to recognize a touch.

It should be noted that, the touch electrode 7 in the figure is aself-capacitance touch electrode and is only illustrative, but not tolimit the solutions in the disclosure. It should be known in the artthat there is no limit to the type of the touch electrode 7 in thedisclosure, the touch electrode 7 may be of a mutual-capacitance touchelectrode or a touch electrode of another type in the prior art, whichwill not be described by taking examples.

Optionally, in this disclosure, the step 102 may be performed before thestep 101.

A step 103, forming a reference mark above the shielding pattern,wherein a color of the reference mark is different from that of theshielding pattern.

With reference to FIG. 4c , the reference mark 9 is formed above theshielding pattern 5 through one patterning process, and the color of thereference mark 9 is different from that of the shielding pattern 5.

In this disclosure, by forming the reference mark 9, the color of whichis different from that of the shielding pattern 5, above the shieldingpattern 5, the reference mark 9 may provide a reference during thesubsequent CNC grinding process, facilitating to monitor the grindingamount of the OGS substrate.

Optionally, in a case that the shielding pattern 5 is formed of a blackmaterial, the reference mark 9 may be made of a white material.

Optionally, in a case that the step 101 is performed before the step102, the formation of the metal wire 8 on the base substrate 1 and theformation of the reference mark 9 above the shielding pattern 5 may beperformed by a single patterning process. It can be seen from above thatthe OGS mother substrate including the reference mark 9 may bemanufactured in the solution of the disclosure without changing theexisting Sensor process procedure. Optionally, materials of both themetal wire 8 and the reference mark 9 are MoAlMo, that is, both themetal wire 8 and the reference mark 9 are of multilayer structures ofMoAlMo, for example, each of the metal wire 8 and the reference mark 9is formed of a first layer of Mo, a second layer of Al and a third layerof Mo, which are sequentially stacked together. The reference mark 9 ofMoAlMo is white.

In order to clearly identify the reference mark 9 through a CCD duringthe CNC grinding process, a size of the reference mark 9 should bedesigned to be as large as possible. However, with the increase of thesize of the reference mark 9, a cost of materials to be consumed isincreased accordingly. With reference to FIG. 6, in this disclosure, inorder to compromise between a difficulty for identifying the referencemark 9 and the material cost, optionally, a width dl of the referencemark 9 ranges from 100 μm to 200 μm.

In addition, in the CNC grinding process, since the view field of theCCD is limited, in order to ensure that the CCD can view both thereference mark 9 and the edge of the OGS substrate simultaneously so asto monitor the grinding amount, it is required that a distance betweenthe reference mark 9 and the edge of the OGS substrate cannot be toolarge, that is, the reference mark 9 should be close to an outer edge ofthe shielding pattern 5 as much as possible. However, in an actualgrinding, in order to prevent light from leaking from edges of the OGSsubstrate as much as possible, generally, the grinding is continued tobe performed for a while after the edge of the chamfer 10 is in contactwith the edge of the shielding pattern 5, that is to say, a part of theouter edge of the shielding pattern 5 may be ground off. In this case,if the reference mark 9 is too close to the outer edge of the shieldingpattern 5, then a part of the reference mark 9 will be ground off. Inview of the above problem, with reference to FIGS. 5 and 6, in thisdisclosure, a distance d2 between the outer edge of the reference mark 9and the outer edge of the shielding pattern 5 may be in a range of 100μm˜200 μm, thus it is ensured that the CCD can view the reference mark 9and the edge of the OGS substrate simultaneously, and the reference mark9 can be effectively prevented from being ground off,

It is found in a practical application that, in a case that thereference mark 9 is an enclosed rectangle frame provided in theperiphery region 3 of the substrate area 2, electrostatic charges in thecentral region 4 of the substrate area 2 cannot pass through theenclosed reference mark 9, but gather in the central region 4. With thegather of the electrostatic charges in the central region 4, dischargeis prone to occur in the central region 4 to breakdown electricaldevices in the central region 4, leading to defects of the OGSsubstrate.

With reference to FIG. 5, in view of the above problem, the referencemark 9 is designed as a dispersion structure including a plurality ofsub-marks separated from each other in this disclosure. In this case,the electrostatic charges in the central region 4 may disperse throughintervals between the sub-marks, avoiding the gather of theelectrostatic charges.

The first embodiment provides a manufacturing method of an OGS mothersubstrate, by forming the reference mark, the color of which isdifferent from the shielding pattern, above the shielding pattern, thereference mark may provide a reference during the subsequent CNCgrinding process, facilitating to monitor the grinding amount of the OGSsubstrate.

Second Embodiment

FIG. 7 is a flow chart of a grinding method provided in a secondembodiment of the present disclosure, and FIG. 8 is a diagram showing acase that an edge of the OGS substrate is being ground in the presentdisclosure. As shown in FIGS. 7 and 8, this grinding method is used toperform a CNC grinding on a edge of an OGS substrate, wherein the OGSsubstrate may be obtained by cutting an OGS mother substratemanufactured by the manufacturing method provided in the above firstembodiment, the OGS substrate comprises: a base substrate 1, wherein ashielding pattern 5 is formed inside a periphery region 3 of the basesubstrate 1, a reference mark 9 is formed above the shielding pattern 5,an orthographic projection of the reference mark 9 on the base substrate1 falls into an orthographic projection of the shielding pattern 5 onthe base substrate 1, and a color of the reference mark 9 is differentfrom that of the shielding pattern 5. The grinding method comprisesfollowing steps 201 through 204.

Step 201, grinding an edge of the OGS substrate to form a chamfer.

In the step 201, the edge of the OGS substrate (that is, the basesubstrate 1) is ground through a grinding apparatus to form a chamfer,wherein a width of the chamfer is about 100 μm.

Step 202, identifying an edge of the reference mark and the edge of theOGS substrate.

In the step 202, the periphery region 3 of the OGS substrate is viewedthrough a CCD, at this time, the chamfer 10 and the shielding pattern 5are exhibited as black in the CCD (if there is a blank region on the OGSsubstrate, then the blank region is white), the reference mark 9 is notexhibited as black, therefore the edges of the reference mark 9 and theOGS substrate can be distinguished through the CCD.

In this embodiment, in order to facilitate the CCD to identify anddistinguish the edges of reference mark 9 and the OGS substrate,optionally, a color of the shielding pattern 5 is black, and a color ofthe reference mark 9 is white. A width d1 of the reference mark 9 rangesfrom 100 μm to 200 μm.

Step 203, calculating a position distance between an outer edge of thereference mark 9 and the edge of the OGS substrate corresponding to theouter edge of the reference mark 9 based on the identified edges of thereference mark and the OGS substrate.

In the step 203, the position distance d3 between the outer edge of thereference mark 9 and the edge of the OGS substrate corresponding to theouter edge of the reference mark 9 is calculated based on an imageobtained by the CCD.

In this disclosure, a position of the reference mark 9 on the shieldingpattern 5 is preset, the position distance d3 between the outer edge ofthe reference mark 9 and the edge of the OGS substrate corresponding tothe outer edge of the reference mark 9 may reflect an amplitude of thegrinding amount to some extent. During the grinding, with the grindingamount increasing, the position distance d3 between the outer edge ofthe reference mark 9 and the edge of the OGS substrate corresponding tothe outer edge of the reference mark 9 is gradually decreased.

Step 204, judging whether the position distance is smaller than a firstdistance.

In the step 204, in a case that it is judged that the position distanced3 is smaller than the first distance, it is indicated that the grindingamount is enough, so the grinding is stopped. In a case that it isjudged that the position distance d3 is larger than or equal to thefirst distance, it is indicated that the grinding amount isinsufficient, it is needed to continue to grind, that is, the above step201 is performed again.

It should be noted that the first distance may be set accordingly asrequired so as to ensure that an inner edge of the chamfer 10 may be incontact with the edge of the shielding pattern 5. For example, it isassumed that a distance d2 between the reference mark 9 and the outeredge of the shielding pattern 5 before the grinding is L1, a width d4 ofthe chamfer 10 is L2, then the first distance may be L1+L2.

It can be seen from above that, during the grinding, by obtaining theposition distance d3 between the reference mark 9 and the correspondingedge of the OGS substrate, the grinding amount of the OGS substrate maybe monitored.

It is should be noted that, in the disclosure, after the CNC grindingprocess is completed, a second screen printing process may be skippedover and a strengthening process of the OGS substrate may be directlyperformed.

Third Embodiment

FIG. 9 is a flow chart of a grinding method provided in a thirdembodiment of the present disclosure. As shown in FIG. 9, the grindingmethod not only includes the step 201 to the step 204, but also includesa step 205. The step 205 will be described in detail below.

In a case that it is judged. that the position distance is smaller thanthe first distance in the step 204, performing the step 205.

Step 205, judging whether the position distance is smaller. than asecond distance.

The second distance is smaller than the first distance. It should benoted that the second distance may be set accordingly as required so asto ensure that an inner edge of the chamfer 10 may be in contact withthe edge of the shielding pattern 5, while the grinding amount of theshielding pattern 5 cannot be excessive (ensuring the size of the OGSsubstrate to meet the production requirements). For example, it isassumed that a distance d2 between the reference mark 9 and the outeredge of the shielding pattern 5 before the grinding is L1, a width d4 ofthe chamfer 10 is L2, then the second distance may be L1+L2−50 μm.

In the step 205, in a case that it is judged that the position distanced3 is larger than or equal to the second distance, it is identified thatthe grinding amount of the OGS substrate is normal. In a case that it isjudged that the position distance d3 is smaller than the seconddistance, it is identified that the grinding amount of the OGS substrateis excessive.

It can be seen from above that, by the grinding method in thisembodiment, not only the grinding amount of the OGS substrate can bemonitored, but also whether or not the grinding amount is excessive canbe judged timely.

Fourth Embodiment

FIG. 10 is a structural diagram of an OGS substrate provided in a fourthembodiment of the present disclosure, and FIG. 11 is a cross sectionaldiagram showing a periphery region 3 on one side of the OGS substrateshown in FIG. 10. As shown in FIGS. 10 and 11, the OGS substrate may beobtained by cutting the OGS mother substrate manufactured by the methodprovided in the first embodiment and grinding the cut. OGS substrate bythe grinding method provided in the second or third embodiment.

The OGS substrate comprises a base substrate 1, a touch structure 6 isformed in a central region 4 of the base substrate 1; and a shieldingpattern 5 is formed in a periphery region 3 of the base substrate 1. Areference mark 9 is formed above the shielding pattern 5, and a color ofthe reference mark 9 is different from that of the shielding pattern 5.An orthographic projection of the reference mark 9 on the base substratefalls into an orthographic projection of the shielding pattern 5 on thebase substrate. A chamfer 10 is formed at an edge of the base substrate1; and a position distance d3 between an outer edge of the referencemark 9 and an edge of the OGS substrate (base substrate 1) correspondingto the outer edge of the reference mark 9 is within a first range.

In this embodiment, a minimum value of the first range is the seconddistance in the above third embodiment, and a maximum value of the firstrange is the first distance in the above third embodiment. Optionally,the second distance may be 200 μm, and the first distance may be 250 μm,that is, the first range may be from 200 μm to 250 μm.

Optionally, a width d1 of the reference mark 9 ranges from 100 μm to 200μm.

Optionally, a color of the shielding pattern 5 is black, and a color ofthe reference mark 9 is white.

Optionally, the reference mark 9 is of a multilayer structure of MoAlMo.

Optionally, the touch structure 6 includes a touch electrode 7 and ametal wire 8 connected to the touch electrode 7, and wherein thereference mark 9 is provided in a same layer as the metal wire 8. Inthis case, the reference mark 9 and the metal wire 8 may be formedthrough a single patterning process.

Optionally, the reference mark 9 is of a dispersion structure includinga plurality of sub-marks separated from each other. The reference mark 9in the dispersion structure facilitates the dispersion of theelectrostatic on the OGS substrate.

This disclosure has following advantages.

This disclosure provides a grinding method, an OGS substrate and amanufacturing method of an OGS mother substrate, wherein the grindingmethod comprises: grinding an edge of the base substrate so as to form achamfer; identifying an edge of the reference mark and the edge of thebase substrate; calculating a position distance between an outer edge ofthe reference mark and the edge of the base substrate corresponding tothe outer edge of the reference mark based on the identified edges ofthe reference mark and the base substrate; judging whether the positiondistance is smaller than a first distance; in a case that it is judgedthat the position distance is smaller than the first distance, stoppinggrinding; and in a case that it is judged that the position distance islarger than or equal to the first distance, continuing to grind the edgeof the base substrate. The solutions in this disclosure can monitor thegrinding amount of the OGS substrate by forming the reference mark, acolor of which is different from that of the shielding pattern, on theshielding pattern, and obtaining the position distance between the outeredge of the reference mark and the edge of the OGS substratecorresponding to the edge of the reference mark during the CNC grindingprocess.

It should be understood that, the foregoing embodiments are onlyexemplary embodiments used for explaining the principle of the presentinvention, but the present invention is not limited thereto. Variousvariations and improvements may be made by a person skilled in the artwithout departing from the protection scope of the present invention,and these variations and improvements also fall into the protectionscope of the present invention.

1. An OGS substrate comprising: a base substrate including a central region and a periphery region; a touch structure formed in the central region; a shielding pattern formed in the periphery region; and a reference mark formed above the shielding pattern, wherein a color of the reference mark is different from that of the shielding pattern; an orthographic projection of the reference mark on the base substrate falls into an orthographic projection of the shielding pattern on the base substrate; a chamfer is formed at an edge of the base substrate; and a position distance between an outer edge of the reference mark and the edge of the base substrate corresponding to the outer edge of the reference mark is within a first range.
 2. The OGS substrate of claim 1, wherein a width of the reference mark ranges from 100 μm to 200 μm.
 3. The OGS substrate of claim 1, wherein a color of the shielding pattern is black, and a color of the reference mark is white.
 4. The OGS substrate of claim 1, wherein the reference mark is of a multilayer structure of MoAlMo.
 5. The OGS substrate of claim 1, wherein the touch structure includes a touch electrode and a metal wire connected to the touch electrode, and wherein the reference mark is provided in a same layer as the metal wire.
 6. The OGS substrate of claim 1, wherein the reference mark includes a plurality of sub-marks separated from each other.
 7. The OGS substrate of claim 1, wherein the first range is from 200 μm to 250 μm.
 8. A grinding method of an edge of an OGS substrate of claim 1, comprising: grinding an edge of the base substrate so as to form a chamfer; identifying an edge of the reference mark and the edge of the base substrate; calculating a position distance between an outer edge of the reference mark and the edge of the base substrate corresponding to the outer edge of the reference mark based on the identified edges of the reference mark and the base substrate; judging whether the position distance is smaller than a first distance; in a case that it is judged that the position distance is smaller than the first distance, stopping grinding; and in a case that it is judged that the position distance is larger than or equal to the first distance, continuing to grind the edge of the base substrate.
 9. The grinding method of claim 8, further comprising: after it is judged that the position distance is smaller than the first distance, judging whether the position distance is smaller than a second distance, wherein the second distance is smaller than the first distance, wherein in a case that it is judged that the position distance is larger than or equal to the second distance, it is identified that a grinding amount of the OGS substrate is normal, and in a case that it is judged that the position distance is smaller than the second distance, it is identified that the grinding amount of the OGS substrate is excessive.
 10. The grinding method of claim 8, wherein a width of the reference mark ranges from 100 μm to 200 μm.
 11. The grinding method of claim 8, a color of the shielding pattern is black, and a color of the reference nark is white. 